[Bug other/89635] New: More ANSI SGR codes in diagnostics?

[dmalcolm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89635

            Bug ID: 89635
           Summary: More ANSI SGR codes in diagnostics?
           Product: gcc
           Version: 9.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          Severity: normal
          Priority: P3
         Component: other
          Assignee: dmalcolm at redhat dot com
          Reporter: dmalcolm at gcc dot gnu.org
  Target Milestone: ---

In the discussion on my GCC 9 usability blog post, reddit user "evaned" said:

> I wonder how plausible it is to cut out one of the lines in each
> "block" and use ANSI escapes to underline the relevant part of code
> instead of putting in the ~~~~~s on its own line?

(in
https://www.reddit.com/r/programming/comments/ayp3gu/usability_improvements_in_gcc_9/ei2n8al/
)

I'm filing this bug to record that idea (possible GCC 10 material).

I wonder if there are other SGR codes that are worth using?  Maybe the
strikethrough code for deletion fix-it hints?